A control system for a high frequency oscillating ventilator (HFOV) includesan oscillator controller and a mean airway pressure (MAP) controller. The HFOVincludes a reciprocating piston which is adapted to generate positive and negativepressure waves for delivery to a patient airway. The oscillator controller comprisesa pair of closed loop control circuits including an oscillator pressure loopand a centering loop which are collectively adapted to regulate frequency andamplitude of piston reciprocations and centering of the piston. The MAP controllercomprises a closed loop control circuit that is adapted for regulating MAP atthe patient utilizing feedback in the form of patient circuit pressure. Likewise,the oscillator controller utilizes patient circuit pressure as well as pistondisplacement feedback in order to regulate movement of the piston.
